[NET]: Fix GSO problems in dev_hard_start_xmit()

Fix 2 problems in dev_hard_start_xmit():

1. nskb->next needs to link back to skb->next if hard_start_xmit()
returns non-zero.

2. Since the total number of GSO fragments may exceed MAX_SKB_FRAGS + 1,
it needs to stop transmitting if the netif_queue is stopped.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index ea2469398bd5..aa8454901719 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1325,9 +1325,12 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 nskb->next = NULL;
                 rc = dev->hard_start_xmit(nskb, dev);
                 if (unlikely(rc)) {
+                        nskb->next = skb->next;
                         skb->next = nskb;
                         return rc;
                 }
+                if (unlikely(netif_queue_stopped(dev) && skb->next))
+                        return NETDEV_TX_BUSY;
         } while (skb->next);
         
         skb->destructor = DEV_GSO_CB(skb)->destructor;